A term used to denote the * thermal illusion of heat that may arise during prolonged intense skin cooling, typically upon the return of skin temperature to a neutral level after intense cooling (for example, on moving indoors after having been outside on a cold day). Paradoxical heat is a physiological response that may be experienced by any individual. However, it may take on pathological dimensions in a number of central as well as peripheral neurological conditions such as frostbite, multiple sclerosis, and peripheral neuropathy. Various hypotheses exist regarding the neurophysiological correlates of paradoxical heat. In healthy subjects, the mediation of paradoxical heat is attributed primarily to peripheral conductance via the slow, unmyelinated C fibres, or via the faster A<5 fibres. However, the established increase in the susceptibility to paradoxical heat in central neurological conditions is strongly suggestive of a central involvement. The nature of this central involvement is unknown, but empirical research would seem to suggest an involvement of the right insular cortex. Conceptually, the term paradoxical heat is used in opposition to * paradoxical cold. Both phenomena are usually classified as illusions, more specifically, as * physiological illusions or * perceiver-distortion illusions.
References
Davis, K.D., Pope, G.E., Crawley, A.P., Mikulis, D.J. (2004). Perceptual illusion of "paradoxical heat" engages the insular cortex. Journal of Neurophysiology, 92, 1248-1251.
Dictionary of Hallucinations. J.D. Blom. 2010.